>As I have now traced, the change is probably associated with updating libxml2
>to 2.9.1+dfsg1-4:
>https://packages.qa.debian.org/libx/libxml2.html
Well done Slavek.
Yesterday I run a new build and I can confirm the problem on Jessie. Tonight I will try out your patch as well and report back.
Anyhow before we push to git, I think we should try to find out what caused the problem. Maybe with a few adjustment somewhere, we will not need to convert all docbooks.
I am a little short of time before the weekend, as already said :(

Cheers
  Michele